Commit Graph

80 Commits

Author SHA1 Message Date
Vedant Kumar cc7b2a55c2 [DAGCombiner] Change the SDLoc on split extloads (2/N)
In DAGCombiner, we try to simplify this pattern:

  ([s|z]ext (load ...))

Conceptually, a new extload which is created while splitting the load
should have the same debug location as the load.

Making this change affects the IROrder of the new load, causing some
test case churn.

In practice, the new location is never different from the location of
the [s|z]ext, at least not during check-llvm or a stage2 build.

Part of: llvm.org/PR37262

Differential Revision: https://reviews.llvm.org/D46156

llvm-svn: 331301
2018-05-01 19:29:15 +00:00
Geoff Berry a2b9011290 Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding"
Re-enable commit r323991 now that r325931 has been committed to make
MachineOperand::isRenamable() check more conservative w.r.t. code
changes and opt-in on a per-target basis.

llvm-svn: 326208
2018-02-27 16:59:10 +00:00
Quentin Colombet 48abac82b8 Revert "[MachineCopyPropagation] Extend pass to do COPY source forwarding"
This reverts commit r323991.

This commit breaks target that don't model all the register constraints
in TableGen. So far the workaround was to set the
hasExtraXXXRegAllocReq, but it proves that it doesn't cover all the
cases.
For instance, when mutating an instruction (like in the lowering of
COPYs) the isRenamable flag is not properly updated. The same problem
will happen when attaching machine operand from one instruction to
another.

Geoff Berry is working on a fix in https://reviews.llvm.org/D43042.

llvm-svn: 325421
2018-02-17 03:05:33 +00:00
Geoff Berry 94503c7bc3 [MachineCopyPropagation] Extend pass to do COPY source forwarding
Summary:
This change extends MachineCopyPropagation to do COPY source forwarding
and adds an additional run of the pass to the default pass pipeline just
after register allocation.

This version of this patch uses the newly added
MachineOperand::isRenamable bit to avoid forwarding registers is such a
way as to violate constraints that aren't captured in the
Machine IR (e.g. ABI or ISA constraints).

This change is a continuation of the work started in D30751.

Reviewers: qcolombet, javed.absar, MatzeB, jonpa, tstellar

Subscribers: tpr, mgorny, mcrosier, nhaehnle, nemanjai, jyknight, hfinkel, arsenm, inouehrs, eraman, sdardis, guyblank, fedor.sergeev, aheejin, dschuff, jfb, myatsina, llvm-commits

Differential Revision: https://reviews.llvm.org/D41835

llvm-svn: 323991
2018-02-01 18:54:01 +00:00
Zvi Rackover 72b0bb1405 X86 Tests: Update more isel tests with FastVariableShuffle feature
Summary:
Added the FastVariableShuffle feature to cases that resembled processors
for which this fearure is on.
For AVX2 there are processors with and w/o this fearue enable.
For AVX512 only KNL does enable this feature so cases which only have
+avx512f were left without the FastVariableShuffle enabled.

Reviewers: RKSimon, craig.topper

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41851

llvm-svn: 322090
2018-01-09 16:26:06 +00:00
Simon Pilgrim a50eec0293 [X86][AVX2] Split more shuffle tests into 'slow' and 'fast' variable shuffles
llvm-svn: 321171
2017-12-20 13:12:34 +00:00
Francis Visoiu Mistrih 25528d6de7 [CodeGen] Unify MBB reference format in both MIR and debug output
As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.

The MIR printer prints the IR name of a MBB only for block definitions.

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix

Differential Revision: https://reviews.llvm.org/D40422

llvm-svn: 319665
2017-12-04 17:18:51 +00:00
Geoff Berry fabedbad11 Revert "Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding""
This reverts commit r314729.

Another bug has been encountered in an out-of-tree target reported by Quentin.

llvm-svn: 314814
2017-10-03 16:59:13 +00:00
Geoff Berry bfc5fb4571 Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding"
Issues addressed since original review:
- Avoid bug in regalloc greedy/machine verifier when forwarding to use
  in an instruction that re-defines the same virtual register.
- Fixed bug when forwarding to use in EarlyClobber instruction slot.
- Fixed incorrect forwarding to register definitions that showed up in
  explicit_uses() iterator (e.g. in INLINEASM).
- Moved removal of dead instructions found by
  LiveIntervals::shrinkToUses() outside of loop iterating over
  instructions to avoid instructions being deleted while pointed to by
  iterator.
- Fixed ARMLoadStoreOptimizer bug exposed by this change in r311907.
- The pass no longer forwards COPYs to physical register uses, since
  doing so can break code that implicitly relies on the physical
  register number of the use.
- The pass no longer forwards COPYs to undef uses, since doing so
  can break the machine verifier by creating LiveRanges that don't
  end on a use (since the undef operand is not considered a use).

  [MachineCopyPropagation] Extend pass to do COPY source forwarding

  This change extends MachineCopyPropagation to do COPY source forwarding.

  This change also extends the MachineCopyPropagation pass to be able to
  be run during register allocation, after physical registers have been
  assigned, but before the virtual registers have been re-written, which
  allows it to remove virtual register COPY LiveIntervals that become dead
  through the forwarding of all of their uses.

llvm-svn: 314729
2017-10-02 22:01:37 +00:00
Craig Topper 87f7381edf [X86] Teach execution domain fixing to convert between FP and int unpack instructions.
llvm-svn: 313508
2017-09-18 03:29:54 +00:00
Elena Demikhovsky 6cab129464 [X86 CodeGen] Optimization of ZeroExtendLoad for v2i8 vector
Load with zero-extend and sign-extend from v2i8 to v2i32 is "Legal" since SSE4.1 and may be performed using PMOVZXBD , PMOVSXBD instructions.

llvm-svn: 313121
2017-09-13 06:40:26 +00:00
Elena Demikhovsky 18ff5c1374 Added "zext" from v2i8 to v2i32. In the next patch I'll optimize the sequence.
llvm-svn: 313052
2017-09-12 17:27:53 +00:00
Sam McCall f71bb198ed Revert "Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding""
This crashes on boringSSL on PPC (will send reduced testcase)

This reverts commit r312328.

llvm-svn: 312490
2017-09-04 15:47:00 +00:00
Geoff Berry 65528f2991 Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding"
Issues addressed since original review:
- Moved removal of dead instructions found by
  LiveIntervals::shrinkToUses() outside of loop iterating over
  instructions to avoid instructions being deleted while pointed to by
  iterator.
- Fixed ARMLoadStoreOptimizer bug exposed by this change in r311907.
- The pass no longer forwards COPYs to physical register uses, since
  doing so can break code that implicitly relies on the physical
  register number of the use.
- The pass no longer forwards COPYs to undef uses, since doing so
  can break the machine verifier by creating LiveRanges that don't
  end on a use (since the undef operand is not considered a use).

  [MachineCopyPropagation] Extend pass to do COPY source forwarding

  This change extends MachineCopyPropagation to do COPY source forwarding.

  This change also extends the MachineCopyPropagation pass to be able to
  be run during register allocation, after physical registers have been
  assigned, but before the virtual registers have been re-written, which
  allows it to remove virtual register COPY LiveIntervals that become dead
  through the forwarding of all of their uses.

llvm-svn: 312328
2017-09-01 14:27:20 +00:00
Hans Wennborg 24775a0a6c Revert r312154 "Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding""
It caused PR34387: Assertion failed: (RegNo < NumRegs && "Attempting to access record for invalid register number!")

> Issues identified by buildbots addressed since original review:
> - Fixed ARMLoadStoreOptimizer bug exposed by this change in r311907.
> - The pass no longer forwards COPYs to physical register uses, since
>   doing so can break code that implicitly relies on the physical
>   register number of the use.
> - The pass no longer forwards COPYs to undef uses, since doing so
>   can break the machine verifier by creating LiveRanges that don't
>   end on a use (since the undef operand is not considered a use).
>
>   [MachineCopyPropagation] Extend pass to do COPY source forwarding
>
>   This change extends MachineCopyPropagation to do COPY source forwarding.
>
>   This change also extends the MachineCopyPropagation pass to be able to
>   be run during register allocation, after physical registers have been
>   assigned, but before the virtual registers have been re-written, which
>   allows it to remove virtual register COPY LiveIntervals that become dead
>   through the forwarding of all of their uses.

llvm-svn: 312178
2017-08-30 22:11:37 +00:00
Geoff Berry feffb0c8af Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding"
Issues identified by buildbots addressed since original review:
- Fixed ARMLoadStoreOptimizer bug exposed by this change in r311907.
- The pass no longer forwards COPYs to physical register uses, since
  doing so can break code that implicitly relies on the physical
  register number of the use.
- The pass no longer forwards COPYs to undef uses, since doing so
  can break the machine verifier by creating LiveRanges that don't
  end on a use (since the undef operand is not considered a use).

  [MachineCopyPropagation] Extend pass to do COPY source forwarding

  This change extends MachineCopyPropagation to do COPY source forwarding.

  This change also extends the MachineCopyPropagation pass to be able to
  be run during register allocation, after physical registers have been
  assigned, but before the virtual registers have been re-written, which
  allows it to remove virtual register COPY LiveIntervals that become dead
  through the forwarding of all of their uses.

llvm-svn: 312154
2017-08-30 18:41:07 +00:00
Geoff Berry bd47e8a4f7 Revert "[MachineCopyPropagation] Extend pass to do COPY source forwarding" round 2
This reverts commit r311135.

sanitizer-x86_64-linux-android buildbot is timing out with just this
patch applied.

llvm-svn: 311142
2017-08-18 01:43:11 +00:00
Geoff Berry 51f52c4fca Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding"
Two issues identified by buildbots were addressed:
    - The pass no longer forwards COPYs to physical register uses, since
      doing so can break code that implicitly relies on the physical
      register number of the use.
    - The pass no longer forwards COPYs to undef uses, since doing so
      can break the machine verifier by creating LiveRanges that don't
      end on a use (since the undef operand is not considered a use).

    [MachineCopyPropagation] Extend pass to do COPY source forwarding

    This change extends MachineCopyPropagation to do COPY source forwarding.

    This change also extends the MachineCopyPropagation pass to be able to
    be run during register allocation, after physical registers have been
    assigned, but before the virtual registers have been re-written, which
    allows it to remove virtual register COPY LiveIntervals that become dead
    through the forwarding of all of their uses.

    Reviewers: qcolombet, javed.absar, MatzeB, jonpa

    Subscribers: jyknight, nemanjai, llvm-commits, nhaehnle, mcrosier, mgorny

    Differential Revision: https://reviews.llvm.org/D30751

llvm-svn: 311135
2017-08-17 23:06:55 +00:00
Geoff Berry 4e38e02e6f Revert "[MachineCopyPropagation] Extend pass to do COPY source forwarding"
This reverts commit r311038.

Several buildbots are breaking, and at least one appears to be due to
the forwarding of physical regs enabled by this change.  Reverting while
I investigate further.

llvm-svn: 311062
2017-08-17 04:04:11 +00:00
Geoff Berry 87f8d25150 [MachineCopyPropagation] Extend pass to do COPY source forwarding
This change extends MachineCopyPropagation to do COPY source forwarding.

This change also extends the MachineCopyPropagation pass to be able to
be run during register allocation, after physical registers have been
assigned, but before the virtual registers have been re-written, which
allows it to remove virtual register COPY LiveIntervals that become dead
through the forwarding of all of their uses.

Reviewers: qcolombet, javed.absar, MatzeB, jonpa

Subscribers: jyknight, nemanjai, llvm-commits, nhaehnle, mcrosier, mgorny

Differential Revision: https://reviews.llvm.org/D30751

llvm-svn: 311038
2017-08-16 20:50:01 +00:00
Igor Breger 293dfb9768 [X86] Add vector zext tests.
llvm-svn: 297581
2017-03-12 13:20:10 +00:00
Simon Pilgrim 9f5c251d57 [X86][SSE] Lower 128-bit vectors to SIGN/ZERO_EXTEND_VECTOR_IN_REG ops
As described on PR31712, we miss a variety of legalization combines because we lower these to X86ISD::VSEXT/VZEXT despite them having the same functionality. This patch makes 128-bit (SSE41) SIGN/ZERO_EXTEND_VECTOR_IN_REG ops legal, adds the necessary tablegen plumbing and uses a helper 'getExtendInVec' to decide when to use SIGN/ZERO_EXTEND_VECTOR_IN_REG or VSEXT/VZEXT.

We're missing a couple of shuffle combines that will be added in a future patch for review.

Later patches can then support the AVX2 cases as a mixture of SIGN/ZERO_EXTEND and SIGN/ZERO_EXTEND_VECTOR_IN_REG, and then finally deal with the AVX512 cases.

Differential Revision: https://reviews.llvm.org/D30549

llvm-svn: 296985
2017-03-05 09:57:20 +00:00
Simon Pilgrim 0f0e5bd3c6 [X86][SSE] Allow matchVectorShuffleWithUNPCK to recognise ZERO inputs
Add support for specifying an UNPCK input as ZERO, particularly improves ZEXT cases with non-zero offsets

llvm-svn: 295169
2017-02-15 11:46:15 +00:00
Craig Topper ff272ad4f3 [SelectionDAG] Teach getNode to simplify a couple easy cases of EXTRACT_SUBVECTOR
Summary:
This teaches getNode to simplify extracting from Undef. This is similar to what is done for EXTRACT_VECTOR_ELT. It also adds support for extracting from CONCAT_VECTOR when we can reuse one of the inputs to the concat. These seem like simple non-target specific optimizations.

For X86 we currently handle undef in extractSubvector, but not all EXTRACT_SUBVECTOR creations go through there.

Ultimately, my motivation here is to simplify extractSubvector and remove custom lowering for EXTRACT_SUBVECTOR since we don't do anything but handle undef and BUILD_VECTOR optimizations, but those should be DAG combines.

Reviewers: RKSimon, delena

Reviewed By: RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29000

llvm-svn: 292876
2017-01-24 02:36:59 +00:00
Simon Pilgrim 55066e5622 [X86][SSE] Add support for combining target shuffles to AND bitmasks.
llvm-svn: 288335
2016-12-01 13:47:02 +00:00
Simon Pilgrim 35c47c494d [X86][SSE] Add initial support for combining target shuffles to (V)PMOVZX.
We can only handle 128-bit vectors until we support target shuffle inputs of different size to the output.

llvm-svn: 288140
2016-11-29 14:18:51 +00:00
Craig Topper 01e4667e02 [AVX-512] Add support for creating SIGN_EXTEND_VECTOR_INREG and ZERO_EXTEND_VECTOR_INREG for 512-bit vectors to support vpmovzxbq and vpmovsxbq.
Summary: The one tricky thing about this is that the sign/zero_extend_inreg uses v64i8 as an input type which isn't legal without BWI support. Though the vpmovsxbq and vpmovzxbq instructions themselves don't require BWI. To support this we need to add custom lowering for ZERO_EXTEND_VECTOR_INREG with v64i8 input. This can mostly reuse the existing sign extend code with a couple checks for sign extend vs zero extend added.

Reviewers: delena, RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D25594

llvm-svn: 285053
2016-10-25 04:00:29 +00:00
Craig Topper d9ca3d97ef [AVX-512] Simplify X86InstrInfo::copyPhysReg for 128/256-bit vectors with AVX512, but not VLX. We should use the VEX opcodes and trust the register allocator to not use the extended XMM/YMM register space.
Previously we were extending to copying the whole ZMM register. The register allocator shouldn't use XMM16-31 or YMM16-31 in this configuration as the instructions to spill them aren't available.

llvm-svn: 280648
2016-09-05 06:43:06 +00:00
Simon Pilgrim 687d71e877 [X86][SSE] Add support for combining target shuffles to PSLLDQ/PSRLDQ byte shifts
llvm-svn: 278502
2016-08-12 11:24:34 +00:00
Simon Pilgrim 69f2299efc [X86][AVX512BW] Add sext/zext AVX512BW 512-bit vector tests
llvm-svn: 277957
2016-08-07 12:41:36 +00:00
Simon Pilgrim a23141eca7 [X86][AVX512] Add sext/zext to 512-bit vector tests
llvm-svn: 277956
2016-08-07 12:10:46 +00:00
Simon Pilgrim 6800a45790 [X86][SSE] Added PSLLDQ/PSRLDQ as a target shuffle type
Ensure that PALIGNR/PSLLDQ/PSRLDQ are byte vectors so that they can be correctly decoded for target shuffle combining

llvm-svn: 272471
2016-06-11 13:38:28 +00:00
Simon Pilgrim cf340bd9c1 [X86][SSE] When lowering a 256-bit shuffle as PMOVZX, reduce the input vector to the lower 128-bit subvector.
Most often as not this is what it started out as, the extraction is zero-cost on AVX and the PMOVZX/PMOVSX folding logic is based around 128-bit loads.

llvm-svn: 270858
2016-05-26 15:40:36 +00:00
Simon Pilgrim 50c37ceb3b [X86][SSE] Added load_zext_16i8_to_8i32 test
Odd issue with input vector not being folded into pmovzx on AVX2+ targets

llvm-svn: 270852
2016-05-26 14:45:30 +00:00
Simon Pilgrim 25fb4177fb [X86][SSE] Reapplied: Simplify vector LOAD + EXTEND on pre-SSE41 hardware
Improve vector extension of vectors on hardware without dedicated VSEXT/VZEXT instructions.

We already convert these to SIGN_EXTEND_VECTOR_INREG/ZERO_EXTEND_VECTOR_INREG but can further improve this by using the legalizer instead of prematurely splitting into legal vectors in the combine as this only properly helps for lowering to VSEXT/VZEXT.

Removes a lot of unnecessary any_extend + mask pattern - (Fix for PR25718).

Reapplied with a fix for PR26953 (missing vector widening legalization).

Differential Revision: http://reviews.llvm.org/D17932

llvm-svn: 264062
2016-03-22 16:22:08 +00:00
Simon Pilgrim 0f37fbac51 [X86][SSE] Simplified blend-with-zero combining
We were being too aggressive in trying to combine a shuffle into a blend-with-zero pattern, often resulting in a endless loop of contrasting combines

This patch stops the combine if we already have a blend in place (means we miss some domain corrections)

llvm-svn: 263717
2016-03-17 15:59:36 +00:00
Eric Christopher da8b3f1914 Temporarily Revert "[X86][SSE] Simplify vector LOAD + EXTEND on
pre-SSE41 hardware" as it seems to be causing crashes during code
generation in halide. PR forthcoming.

This reverts commit r263303.

llvm-svn: 263512
2016-03-14 23:59:57 +00:00
Simon Pilgrim 33d57c7547 [X86][SSE] Simplify vector LOAD + EXTEND on pre-SSE41 hardware
Improve vector extension of vectors on hardware without dedicated VSEXT/VZEXT instructions.

We already convert these to SIGN_EXTEND_VECTOR_INREG/ZERO_EXTEND_VECTOR_INREG but can further improve this by using the legalizer instead of prematurely splitting into legal vectors in the combine as this only properly helps for lowering to VSEXT/VZEXT.

Removes a lot of unnecessary any_extend + mask pattern - (Fix for PR25718).

Differential Revision: http://reviews.llvm.org/D17932

llvm-svn: 263303
2016-03-11 22:18:05 +00:00
Simon Pilgrim 61eb49e437 [X86][SSE] Reapplied: Improve vector ZERO_EXTEND by combining to ZERO_EXTEND_VECTOR_INREG
Generalise the existing SIGN_EXTEND to SIGN_EXTEND_VECTOR_INREG combine to support zero extension as well and get rid of a lot of unnecessary ANY_EXTEND + mask patterns.

Reapplied with a fix for PR26870 (avoid premature use of TargetConstant in ZERO_EXTEND_VECTOR_INREG expansion).

Differential Revision: http://reviews.llvm.org/D17691

llvm-svn: 263159
2016-03-10 20:40:26 +00:00
Hans Wennborg e00b6e7249 Revert r262599 "[X86][SSE] Improve vector ZERO_EXTEND by combining to ZERO_EXTEND_VECTOR_INREG"
This caused PR26870.

llvm-svn: 262935
2016-03-08 16:21:41 +00:00
Simon Pilgrim 91dd0a796c [X86][SSE] Improve vector ZERO_EXTEND by combining to ZERO_EXTEND_VECTOR_INREG
Generalise the existing SIGN_EXTEND to SIGN_EXTEND_VECTOR_INREG combine to support zero extension as well and get rid of a lot of unnecessary ANY_EXTEND + mask patterns.

Differential Revision: http://reviews.llvm.org/D17691

llvm-svn: 262599
2016-03-03 09:43:28 +00:00
Simon Pilgrim 3b6feeaa7c [X86][SSE41] Combine vector blends with zero
Part 2 of 2
This patch add support for combining target shuffles into blends-with-zero.

Differential Revision: http://reviews.llvm.org/D17483

llvm-svn: 261745
2016-02-24 15:14:21 +00:00
Simon Pilgrim a50e8d3627 [X86][AVX] Support bit-mask integer shuffles for 256-bit integer vectors
AVX1 doesn't support the shuffling of 256-bit integer vectors. For 32/64-bit elements we get around this by shuffling as float/double but for 8/16-bit elements (assuming they can't widen) we currently just split, shuffle as 128-bit vectors and concatenate the results back.

This patch adds the ability to lower using the bit-mask patterns before defaulting to the splitting behaviour. In some cases this ends up matching what AVX2 would do anyhow or what AVX1 does on the split vectors.

Part 1 of 2

Differential Revision: http://reviews.llvm.org/D17292

llvm-svn: 261081
2016-02-17 10:37:49 +00:00
Simon Pilgrim f116e4acc7 [X86][SSE] Resolve target shuffle inputs to sentinels to permit more combines
The combineX86ShufflesRecursively only supports unary shuffles, but was missing the opportunity to combine binary shuffles with a zero / undef second input.

This patch resolves target shuffle inputs, converting the shuffle mask elements to SM_SentinelUndef/SM_SentinelZero where possible. It then resolves the updated mask to check if we have created a faux unary shuffle.

Additionally, we now attempt to recursively call combineX86ShufflesRecursively for all input operands (we used to just recurse for unary integer shuffles and unary unpacks) - it safely returns early if its not a target shuffle.

Differential Revision: http://reviews.llvm.org/D16683

llvm-svn: 260063
2016-02-07 22:51:06 +00:00
Simon Pilgrim 0acc32a3b3 [X86][AVX512] Added support for VPMOVZX shuffle decoding.
llvm-svn: 260007
2016-02-06 19:51:21 +00:00
Simon Pilgrim 8159cf11bc [X86] Add AVX512 vector zext tests
llvm-svn: 259786
2016-02-04 14:06:19 +00:00
Simon Pilgrim 12e71db856 [X86][SSE] Added 8i8 to 8i64 sext/zext tests
llvm-svn: 258868
2016-01-26 22:19:22 +00:00
Simon Pilgrim 17377bdd45 [X86][AVX] Only shuffle the lower half of vectors if the upper half is undefined
First step towards making better use of AVX's implicit zeroing of the upper half of a 256-bit vector by instructions that only act on the lower 128-bit vector - discussed on D14151.

As well as the fact that 128-bit shuffle instructions are generally more capable, this can be performant for older CPUs with 128-bit ALUs (e.g. Jaguar, Sandy Bridge) that must treat 256-bit vectors as multiple micro-ops.

Moved the similar subvector extraction shuffle combines from PerformShuffleCombine256 to lowerVectorShuffle as well.

Note: I've avoided combining shuffles that reference elements from the upper halves of the input vectors - this may be reviewed in future work as well (AVX1 would probably always gain, but AVX2 does have some cross-lane shuffle instructions).

Differential Revision: http://reviews.llvm.org/D15477

llvm-svn: 256332
2015-12-23 13:10:07 +00:00
James Y Knight 7c905063c5 Make utils/update_llc_test_checks.py note that the assertions are
autogenerated.

Also update existing test cases which appear to be generated by it and
weren't modified (other than addition of the header) by rerunning it.

llvm-svn: 253917
2015-11-23 21:33:58 +00:00
Simon Pilgrim 40ada57b7e [X86][SSE] vector sext/zext tests - remove unnecessary mcpu arguments
llvm-svn: 251233
2015-10-25 12:15:00 +00:00